Variable electric condenser



Nov. 3, 1925. 1,559,974

6, J, MULLIGAN VARIABLE ELECTRIC qonpgnsgg Filed March 8, L924 HII HI! FIGJ J r E 2 4. /7- i: I

Z 1 20 E l I is INVENTOR.

GERALD J|MULLIGAI-I By ATTORNEY Patented Nov. 3, 1925 GERALD J. MULLIGAN, OF COLUMBUS, OHIO.

VARIABLE ELECTRIC CONDENSER.

Application filed March 8, 1924 Serial No. 697,839.

T0 0?] 7071 am it may concern.

Be it known that I, GERALD J, MULLIGAN, a citizen of the United States of America. residing at Columbus, in the county of Franklin and State of Ohio, have invented certain new and useful Improvements in Variable Electric Condensers, of which the following is a specification.

My present invention relates generally to condensers and more particularly to an electrical condenser, my object being the provision of a variable electric condenser which will be extremely simple and inexpensive as well as one having a wide range capacity and will be capable of extremely sensitive adjustment or variation, and a further object is the provision of a concenser of this type which will avoid all danger of short circuiting.

Vith these objects in mind my invention proposes a condenser wherein one of the electrodes is in the term of a liquid or fluid conductor and wherein means are employed to vary the relative areas of the two electrodes over a wide range so that fine adjustment may be easily efl'ected and my inven tion further proposes a. variable condenser wherein one of the electrodes is inthe form of liquid or fluid conductor and is utilized in connection with means to vary the level of the liquid or fluid electrodes with respect to another relatively stationary electrode and in this way increase or decrease the area of the fluid electrode with respect to the stationary electrode so as to vary the capacity of the condenser.

In the accompanying drawing which illustrates my present invention and forms a part of this specification,

Figure 1 is a side elevation showing my improved condenser,

Figure 2 is a sectional view taken therethrough showing the parts in position with the condenser at low capacity,

Figure 3 is a cross section taken substantially on line 33 of Figure 1, and

Figure at is a view similar to Figure 2, showing the core or plunger adjusted to raise the level of the liquid or fluid electrode and thus increase the capacity of the condenser.

Referring now to these figures my invention proposes a condenser including a cylindrical container or receptacle which constitutes the dielectric and which is preferably in the form of a glass jar closed at its base and also having an upper closure in the form of a cap 11 threaded or otherwise held thereon, the receptacle being thus adapted to contain a liquid or fluid conductor 12 therein, which may be mercury, salt water, dilute acid. or other material suitable for the purpose, this liquid. or-fluid concuctor forming one electrode or one side of the condenser. Through the lower portion ot the receptacle or jar 10 a binding post may be extended, with a clamping nut V to hold the same in place with suitable washers 15 against the inner and outer surfaces of the receptacle for preventing leakage, and with a binding post 16 upon its outer portion for the usual purpose, the inner end of the binding post being thus immersed at all times within the liquid or fluid conductor.

The other conductor of a stationary nature is formed by a layer of tinfoil or other conducting material 1'? disposed around the jar or receptacle 10, the ends of which are preferably spaced apart as shown in Figure 1 so that the heighth ot the fluid conductor 12 may be viewed through the jar or receptacle, assuming the latter to be of transparent material. Adjacent to its (l spaced ends, the outer stationary electrode 17 which may be glued or otherwise aflixed to the external surface or the receptacle 10 as a coating for the latter, may be provided with vertical lines or graduations 18, whereby the value of any particular level of the liquid or fluid electrode may be readily determined with respect to the full capacity of the condenser represented by a level of the fluid at the upper edge of the outer coating or electrode 17.

Around the outer coating 01' electrode 17. a band 19 may be fixed by virtue of a clamping bolt 20 extending through its opposed flanged ends 21, the bolt being preferably extended to form a binding post and provided with a binding nut 22.

By reference to Figure 2 it will be noted that the normal level of the liquid or fluid electrode 12 is adjacent to the lower edge of the outer coating or electrode 17 and that upon downward movement of a core or plunger 23 within this fluid, its level is raised around the core or plunger between the latter and the wall of the receptacle 10 so as to thus increase the area of the liquid or fiuidwith respect to that of the outer stationary electrode 17 and in this way increase the capacity of the condenser.

For the above purpose the plunger or core 23 is properly proportioned in size with respect to the diameter of the receptacle 10 and the amount of fiuid 12 constituting the adjustable electrode, whereby the level of the fluid will be raised to a point opposite the upper edge of the outer electrode 17 when the plunger or core is in lowermost position. This plunger or core is formed of any suitable non-conducting material and has an upstanding axial stem 2% threaded through a central bearing 25 of the receptacle cap 11, the stem'having upon its upper external end a milled knob or handle 26 whereby it maybe easily and conveniently rotated to either raise or lower the core or plunger 23 in varying the capacity of the condenser. In order to facilitate the mounting of the condenser as a whole, the receptacle cap 11 may also have openings 27 for the reception of clamping bolts such as seen at 28 in Figure 2, by means of which the condenser as a whole may be held in suspended relation from a horizontal panel or support indicated in dotted lines at 29 in Figure 2.

It is obvious, however, that the condenser as a whole may be otherwise suitably sup ported, that its parts may be formed of various materials suitable for their respective purposes, and that these parts as previously described are not only such as to permit of easy and fine adjustments of the capacity of the condenser but are also such as to create a wide range of adjustment and elfectively prevent all danger of short circuits.

I claim:

1. A variable condenser including a receptacle in the form of a fluid container, constituting a dielectric and having an external coating lined thereto and constituting an external stationary electrode, a clamp surrounding the receptacle in contact with the coating and around the lower edge thereof and having abinding post, a binding post fixed through the wall of the receptacle below and apart from the coating thereof, a fluid conducting material within the receptacle whose normal level is adjacent to the lower edge of the external stationary electrode, a cap closing the upper end of the receptacle and having a central bearing,

core or plunger withln the receptacle,

and a formed of insulating material for movement downwardly into the fluid and operat ing solely to raise the level of the latter with respect to the outer elcetrode, having an upright stein threaded through the bearing of the cap and provided with an external knob or handle for the purpose described.

2. A variable condenser including a receptacle in the form of a fluid container, constituting a dielectric and having an external coating fined thereto and constituting an external stationary electrode, a clamp surrounding the receptacle in contact with the coating and around the lower edge thereof and having a binding post, a binding post fixed through the wall of the receptacle below and apart from the coating thereof, a fluid conducting material within the receptacle whose normal level is adjacentito the lower edge of the external stationary electrode, a cap closing the upper end of the receptacle and having a central bearing, and a core or plunger within the receptacle formed of insulating material for movement downwardly into the fluid and operating solely to raise the level of the latter with respect to the outer electrode, having an upright stem threaded through the bearing of the cap and provided with an external knob or handle, said receptacle being formed of transparent material and said coating thereof having its ends horizontally spaced apart to form a vertical sight channel and having lines or graduation vertically along its said spaced ends at opposite sides of said channel for the purpose described.

dielectric in the form of a receptacle, a fixed electrode around the receptacle, a liquid or lluid conductor within the receptacle forming the adjustable electrode and normally on a level adjacent to the lower edge of the fixed electrode, a dielectric plunger or core shiftable vertically Within the receptacle into and out of the fluid electrode and operat ing solely to raise and lower the level of the fluid, and means for raising and lowering said core or plunger. 1

In testimony whereof I have afixed my signature.

GERALD J. NFULLIGAN.

o. A variable condenser consist-ing of a' 

